Microsoft co-founder Paul Allen has announced that he has launched a raft of patent infringement lawsuits against some of the giants of the Internet search space, including Google, Apple, Yahoo, eBay, Facebook, YouTube and AOL.

Although Mr. Allen departed from Microsoft in 1983, the lawsuit, filed in a Seattle federal court on Friday, did not name the company that he and Bill Gates founded back in 1975.

According to reports, the lawsuit filed by Mr. Allen's company, Interval Research, focussed on four patents related to consumers' website interface during Internet searches, which it said it had patented over a decade ago.

One patent was said to enable the navigation of audiovisual data, another facilitated quick location of information related to a specific subject, and two further patents enhanced websites' presentation of images or data on “users' peripheral attention.”

Google reacted angrily to the suit, with one of its spokespersons quoted as saying, “This lawsuit against some of America's most innovative companies reflects an unfortunate trend of people trying to compete in the courtroom instead of the marketplace.” The company further said that innovation and not litigation was the way to bring to market the products and services that benefitted millions of people around the world.

Facebook also attacked the lawsuit, saying, “We believe this suit is completely without merit and we will fight it vigorously.”

Besides Microsoft, the other notable absentee from the list of companies sued was Amazon, the online retailer. Mr. Allen's Vulcan Inc. investment firm was noted to have developed Amazon's new headquarters in Seattle.

Among the other firms sued by Mr. Allen are Netflix, Office Depot, OfficeMax and Staples, all engaged in online retailing.